1. Technical Field
The present invention relates to an organic electroluminescent device, a method for manufacturing the same, and an electronic apparatus including the same.
2. Related Art
As information apparatuses are being diversified, lightweight, planar, power-saving display devices are increasingly desired. Among those are organic electroluminescent devices (hereinafter referred to as organic EL devices) having an organic luminescent layer.
The organic EL device includes a luminescent layer, a hole injection layer, and an electron injection layer. Many of the materials of these layers easily react with water in the air and thus easily deteriorate. If these layers deteriorate, a so-called “dark spot”, where light is not emitted, occurs in the organic EL device and is a cause of a short-life light-emitting element. In order to prevent water or oxygen from permeating the light emitting elements, a structure has been proposed in which the light-emitting elements are sealed with a highly moisture-resistant thin film (for example, Japanese Unexamined Patent Application Publication No. 2001-230086).
The organic EL device generally includes an element substrate and a sealing substrate that are bonded together with an adhesive layer in between. Unfortunately, air bubbles are trapped in a step or an uneven portion on the surfaces of the color layers or the light-shielding layer when the adhesive layer is formed. In order to solve this problem, it is proposed that an overcoat layer is provided on the surfaces of the color layers and the light-shielding layer to alleviate the step or the unevenness for even surfaces. The overcoat layer is made of a non-water absorbable material from the viewpoint of preventing the color layers and the light-shielding layer from being degraded by water. Unfortunately, non-water absorbable overcoat layers are generally not wettable to the liquid material of the adhesive layer. If the overcoat is less wettable to the liquid material of the adhesive layer, the liquid material of the adhesive layer cannot easily fill a desired space and it takes a long time to fill the space.
The overcoat layer disposed between the two substrates increases the distance between the organic luminescent layers and the color layers. In a top emission organic EL device, a large distance between the organic luminescent layers and the color layers requires that the area of the light-shielding layer is increased to prevent light from leaking to the adjacent pixels. Consequently, the aperture area of the color layers is reduced, and the extraction efficiency of emitted light is degraded accordingly.